Installing Java and Elasticsearch

First, let's install Elasticsearch and its dependencies. Apache Lucene and Elasticsearch are both written in Java, and so we must first install Java.

Installing Java

When you install Java, it usually means one of two things: you are installing the Java Runtime Environment (JRE) or the Java Development Kit (JDK). The JRE provides the runtime that allows you to run Java programs, whereas the JDK contains the JRE, as well as other tools, that allow you to develop in Java.

We are going to install the JDK here, but to complicate things further, there are different implementations of the JDK—OpenJDK, Oracle Java, IBM Java—and the one we...